Quote:
Originally Posted by WingnutR32
Stacking will only give a better signal to noise ratio. If you have 30 images of 30 seconds stacked, you still only have 30 seconds of signal, but your noise will decrease.
If you have 1 image of 30 minutes, you will have a heap of detail, but possibly high noise (depending on hardware).
So no, stacking won't give similar results, stacking is only used to improve the signal to noise ratio.
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I disagree with the assertion that stacking short exposures results in less noise than a single exposure of the same total length.
There are several different sources of noise. A major and unavoidable source of noise is called "shot noise" and is a consequence of the quantum nature of light. The magnitude of the shot noise is determined by the square root of the number of photons detected and will be the same so long as the total exposure time is the same.
Other sources of noise are internal to the sensor itself, e.g. read noise. This type of noise will be worse in the situation where you are doing multiple exposures as you will incur this noise multiple times.
You will get the best S/N ratio by doing one long exposure, however, that may not be practical for a number of reasons, e.g. exceeding the full well depth of the sensor, inability to guide accurately for long periods, the possibility of losing an exposure due to clouds, etc.
You'll get the best results by making your exposures as long as you can practically make them given the constraints such as those mentioned above...
Cheers,
Rick.